Projectile having a useful charge which must be released at a point on the projectile trajectory



M. FRANCOIS Jan. 27, 1970 3,491 E WHICH MUST BE RELEASED PHOJECTILEHAVING A USEFUL CHARG- AT A POINT ON THE PROJECTILE TRAJECTORY 4Sheets-Sheet l Filed June '7, 1968 Jan. 27, 1970 M FRANcoxs 3,491,689

PROJECTILE HAVING A'USEl-TUL CHARGE WHICH MUST BE RELEASED AT A POINT ONTHE PROJECTILE TRAJECTORY Filed June 7, 1968. 4 Sheets-Sheet 2 Jan. 27,1970 M. FRANCOIS 3,491,539

PROJECTILE HAVING A USEFUL CHARGE WHICH MUST BE RELEASED AT A POINT ONTHE PROJECTILE TRAJECTORY Filed June '7, 1968 4 Sheets-Sheet :5

Jn. 27, 1970 M. FRANCOIS 3,491,689

PROJECTILE HAVING A USEFUL CHARGE WHICH MUST BBRELEASED AT A' POINT ONTHE PROJECTILE TRAJECTORY Filed June 7, 1968 4 Sheets-Sheet 4 UnitedStates Patent O Int. Cl. F42b13/38, 25/02 U.S. Cl. 102-35.6 4 ClaimsABSTRACT OF THE DISCLOSURE Projectile having a fuze igniting a usefulcharge and a charge for ejecting said useful charge. The latter isconnected to a braking parachute and the projectile base contains aprojectile tilting charge and carries a lateral nozzle at the rear ofthe centre of gravity of the projectile for creating, under the elfectof the gases produced by the tilting charge and ejected through thenozzle, a couple which tilts the projectile on its trajectory. Delaymeans are disposed between the fuze and the ejecting and tilting chargesso that combustion of the tilting charge precedes ignition of theejecting charge.

The present invention relates to projectiles of the type having a usefulcharge, such as an illuminating or flare charge which must be releasedat a point on the trajectory and then braked relative to the rest of theprojectile.

In known projectiles of this type, the useful charge is usuallyseparated from the rest of the projectile at a given point on thetrajectory by means of a time fuze containing a small explosive chargeof the black powder type and a clock mechanism which is set beforetiring the projectile. The useful charge is provided with a parachutewhich opens at the moment of separation and, owing to the braking actionthereof, allows the useful charge to continue its descent at low speed.Now, at the moment of separation, the projectile splits up into aplurality of parts. Some of these parts are heavy and large and, incontinuing on their trajectory at a speed in the neighbourhood of thatof the projectile at the moment of separation, can encounter the canopyof the open parachute or the partly-open parachute so that there is arisk of tearing this canopy or preventing its opening. The base of theprojectile constitutes in fact the most dangerous part for this canopyowing to its weight and position. This part of the projectile is heavysince, when firing, it must be capable of withstanding the thrust of thegases and consequently its wall is thick and strong. Further, this basecarries in many cases a rear iin structure or, when it concerns aself-propelling projectile, propelling means. It must be realised that,upon separation of the useful charge and the opening of the brakingparachute, the risk of the base of the projectile damaging the parachuteincreases very rapidly with the dimensions of the parachute and thisnecessitates limiting the weight of the useful load and consequently thecharacteristics of the projectile.

The object of the invention is to provide a projectile of theaforementioned type which remedies these drawbacks.

The projectile according to the invention is of the type comprising atime fuze for igniting the useful charge and an explosive ejectingcharge adapted to eject, from the body of the projectile, the usefulcharge which is connected to a braking parachute, wherein the base ofthe projectile contains, in addition to said charge for ejecting saiduse- Lit() 3,491,689 Patented Jan. 27, 1970 ful charge, a projectiletilting charge and carries a lateral nozzle which is located at the rearof the centre of gravity of the projectile so as to create, under theeffect of the ejection of gases produced by the combustion ofsaidtilting charge, a couple which tilts the projectile, delay means beingdisposed between said fuze and said ejecting and tilting charges wherebythe combustion of said tilting charge precedes the ignition of saidejecting charge.

The ignition of the time fuze therefore rst produces the ignition of theuseful charge and tilting charge, the projectile tilts owing to theejection of the gases through the lateral nozzle, then the useful chargeis expelled with its parachute in a direction parallel to the axis ofthe tilted projectile, that is, at an angle relative to the tangent tothe trajectory of the projectile, and consequently the canopy of theparachute opens off the trajectory of the -body of the projectile sothat the latter cannot damage it.

Further features and advantages of the invention will be apparent fromthe ensuing description with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a longitudinal sectional view of a projectile according to theinvention;

FIG. 2 is a cross-sectional View taken along line 2-2 of FIG. l;

FIG. 3 is a partial detail longitudinal sectional view of the projectileon a scale larger than that of FIG. l, and

FIGS. 4-8 are diagrams showing the elements of the projectile in thevarious stages on the projectile trajectory.

In the illustrated embodiment, the invention is applied to a projectilecomprising a head A, a body B, a base C and a n structure D carried bythe latter. This projectile contains a useful charge or load E which, inthe presently-described embodiment, is an illuminating device or flare.

The head A of the projectile comprises a time fuze 1 containing anadjustable delay means and an explosive charge 2 of the black powdertype fixed on a support 3.

The body B of the projectile comprises a cylindrical case 4 the frontend of which is connected to the support 3 by shearable pins 5. Thisbody contains the useful charge or load E consisting of a container 6containing an illuminating charge 7 which can be ignited by the charge 2of the fuze through pyrotechnic delay means 8.

Fixed to this container 6 by a `cable 9 and suspending lines 9a (seeFIG. 7) is the canopy 10 of a parachute. This canopy is disposed in anenvelope consisting of two half-shells 11 and 11a and a pot 12. Thehalf-shells 11 and 11a and the pot 12 are retained in the body 4 by aring 13 which bears against a flange 14 on the pot and is merely a tightit in the body 4. Screwed in this ring 13 is the front end of the baseC.

The body of the projectile has an axial tube 15 which extendstherethrough and transmits rearwardly the iiames from the combustion ofthe igniting charge 2 to two rear charges 16 and 17 by lway of delayapertures 18, 19.

The charge 16 can ignite, through pyrotechnic delay means 20 (FIGS. 1and 2), a pot ejecting charge 21, whereas the charge 17 can ignite,through apertures 22, an auxiliary propelling charge 23 the ignition ofAwhich produces propelling gases which are ejected through the bore 24of a lateral nozzle 25, after expulsion of a closing plug 26 by thepressure of said gases.

The delay means 8, 20, 22 are such that the operation of the fuze 1 andthe ignition of the charge 2 at time T results, rstly, in the ignition,by way of the apertures 22, of the propelling charge 23 whose combustionlasts about 0.04 second and, then, the ignition by way of the delaymeans 20, of the potejecting charge 21, at about time T|0.06 second,and, nally, the ignition, by way of the delay means 8, of the usefulcharge 7 at about time T+l second.

The projectile therefore operates in the following manner:

At the end of time T, adjusted by the fuze, the latter ignites thecharge 2. The projectile is at P1 on its trajectory. It is for examplepropelled at a speed V of the order of 200 metres per sec.

The propelling charge 23 is ignited and burns from about T to T-l-0.04second. The gases it produce eject the lateral plug 26 and then the jetI of these gases (FIG. 4) gives rise to a lateral reaction force Rlocated to the rear of the centre of gravity G of the completeprojectile. The latter therefore tilts on its trajectory. At timeT-l0.04 second, the projectile has tilted to the position P2 (FIG. 5)and its longitudinal axis then makes an angle of, for example, 30 withthe tangent T of the trajectory. At this moment, the combustion of theauxiliary charge 23 has stopped Ibut the projectile continues to tiltunder the effect of the inertia of the impulse and reaches, at timeT-|0.06 second, the position P3 for example inclined at 40. At thismoment, the pot-ejector charge 21 is ignited, while the speed of theprojectile is still V.

This charge 21 explodes and the pins 5 shear under the effect of thepressure created and the contents of the projectile, namely the fuze 1,the charge E and the parachute with its envelope (11, 12) is expelledforwardly in a direction parallel to the longitudinal axis of theprojectile (FIG. 6) with a speed v relative to the assembly (body E,base C, fin structure D) for example of the order of 10-20 metres persec.

Within a few hundredths of a second, for example at T+0.l0 second, theuseful charge E has travelled through a few decimetres relative to theassembly (E, C, D) and the angle of tilt is then about 45 (FIG. 6).

` At about T+O.l2 second, the canopy 10 of the parachute starts to openat the end of the suspending lines 9a, which connect it to the charge Ethrough the cable 9, whereas the half-shells 11, 11R and the pot 12 areseperated therefrom (FIG. 7).

The relative disposition of the canopy 10` of the parachute and of therear assembly (B, C, D) is then such (FIG. 8) that, lwhen the parachuteis completely open, its canopy is to the rear of this assembly andoffset therefrom a distance a of the order of at least 30 cm. and,thereafter, said assembly of dangerous parts continues its travel at thespeed V (of the order of 200 metres per sec.), whereas the charge Eslows down from 200 metres per sec. to v=about 5 metres per sec. owingto the braking action of the parachute, there being no risk of adangerous part encountering the parachute.

The arrangement according to the invention has therefore the followingadvantages:

There is no longer any risk of the canopy of the parachute being damagedby the parts B, C, D and the charge E, ignited at time T-j-l second,descends slowly in producin g the desired eifect (illumination in thepresent case).

The device is of utility for projectiles of small calibre (-81 mm.)since it requires very little space.

The assembly is very strong owing to the fact that the shearable pins 5are located in the front part of the projectile, since the assembly A,B, C, constitutes a rigid unit.

What I claim is:

1. A projectile comprising a body having a base and, disposed in saidbody: a useful charge which must be released at a point on theprojectile trajectory, a braking parachute connected to said usefulcharge, an explosive ejecting charge disposed in said base and adaptedto eject from said body said useful charge, a time-delay fuze having afuze charge communicating with said useful charge and said ejectingcharge for igniting said useful and ejecting charges, said basecontaining, in addition to said ejecting charge, a projectile tiltingcharge which communicates with said fuze charge, said ybase including alateral gas ejection nozzle which communicates with said tilting chargeand is located to the rear of the centre of gravity of the projectileand so oriented as to eject laterally gases produced by the combustionof said tilting charge and create a moment which tilts the projectile,and delay means interposed between said fuze charge and said ejectingcharge and between said fuze charge and said tilting charge andaifording a delay differential which ensures that the combustion of saidtilting charge precedes the ignition of said ejecting charge.

2. A projectile as claimed in claim 1, wherein said body constituteswith said base a rigid assembly and is connected in the front part ofthe projectile to a support of said fuze by shearable pins.

3. A projectile as claimed in claim 1, comprising an envelope for saidparachute, said envelope comprising the combination of two adjacentfreely disposed half-shells and a rear frustoconical pot.

4. A projectile as claimed in claim 1, comprising an axial tubecommunicating with said fuze charge, an axial powder charge located tothe rear of said axial tube and communicating with said fuze charge viasaid tube so that said axial tube transmits the flames produced by saidfuze charge to said axial powder charge, said ejecting and tiltingcharges communicating with said axial powder charge through said delaymeans.

References Cited UNITED STATES PATENTS 2,362,534 11/1944 Brandt 102-35VERLIN R. PENDEGRASS, Primary Examiner U.S. Cl. X. R.

IGZ- 49.4

